code: def test_decode_online_filters():
      """Tests for online low/high-pass filter decoding."""
      info = _empty_info(100.0)
      highpass = np.array([0.0, 0.1])
      lowpass = np.array([50, 50])
      with pytest.warns(
          RuntimeWarning, match="different highpass filters"
      ):
          _decode_online_filters(info, highpass, lowpass)
      assert info["highpass"] == 0.1
  
      info = _empty_info(100.0)
      highpass = np.array([0.0, 0.0])
      lowpass = np.array([40, 50])
      with pytest.warns(
          RuntimeWarning, match="different lowpass filters"
      ):
          _decode_online_filters(info, highpass, lowpass)
      assert info["lowpass"] == 40
  
      info = _empty_info(100.0)
      highpass = np.array(["NaN", "NaN"])
      lowpass = np.array(["NaN", "NaN"])
      _decode_online_filters(info, highpass, lowpass)
      assert info["highpass"] == 0.0
      assert info["lowpass"] == 50.0
  
file_path: mne-python/mne/io/nsx/tests/test_nsx.py
imports: import os
  import numpy
  import pytest
  from numpy.testing import assert_allclose
  from mne import make_fixed_length_epochs
  from mne._fiff.constants import FIFF
  from mne._fiff.meas_info import _empty_info
  from mne.datasets.testing import data_path, requires_testing_data
  from mne.io import read_raw_nsx
  from mne.io.nsx.nsx import _decode_online_filters, _read_header
  from mne.io.tests.test_raw import _test_raw_reader
label_desc: Use image node_id 1 for calling a global function with example usage: test_decode_online_filters() without return types